Electronic battery tester configured to predict a load test result based on open circuit voltage, temperature, cranking size rating, and a dynamic parameter

- Midtronics, Inc.

A method and apparatus is provided for rapidly and safely estimating the high-rate load test voltage of a storage battery utilizing open-circuit voltage, temperature and a dynamic parameter such as conductance or resistance. An output indicative of the condition of the battery is provided as a function of the estimated load test voltage of the battery compared to industry standards without the necessity to charge the battery or discharge the battery with high-rate loads using bulky load testing equipment.

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Description
CROSS REFERENCE TO RELATED APPLICATION

The present application is based on and claims the benefit of U.S. provisional patent application Ser. No. 60/408,542, filed Sep. 5, 2002, the content of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to testing storage batteries. More specifically, the present invention relates to predicting a high-rate load test result for a storage battery by using a dynamic parameter testing technique such as a conductance testing technique.

Storage batteries, such as lead acid storage batteries of the SLI (Starting, lighting and ignition) type used in the automotive industry, have existed for many years. However, understanding the nature of such storage batteries, how such storage batteries operate and how to accurately test such batteries has been an ongoing endeavor and has proved quite difficult.

There has been a long history of attempts to accurately test the condition of storage batteries for starting and other high-rate applications. A standard technique for testing a battery is referred as the Adjustable Load Test. This test is conducted on a charged battery according to the Battery Service Manual of the Battery Council International:

  • 1) Measure the temperature of a center cell. Cover battery with a damp cloth.
  • 2) Connect a voltmeter and load test leads to the appropriate battery terminals. Be sure the terminals are free of corrosion.
  • 3) Apply a test load equivalent to 50% of the Cold Cranking Ampere Performance (CCA) at 0° F. rating of the battery for 15 seconds.
  • 4) Read and record the voltage at 15 seconds; remove the load.
  • 5) Determine the minimum passing voltage based on the battery's test temperature:

a) 70° F. and above: 9.6 V b) 60° F. 9.5 V c) 50° F. 9.4 V d) 40° F. 9.3 V e) 30° F. 9.1 V f) 20° F. 8.9 V g) 10° F. 8.7 V h)  0° F. 8.5 V
  • 6) If the test voltage is above the minimum, return the battery to service.
  • 7) If test voltage is below the minimum and the stable battery open circuit voltage is above 12.4 volts (75% state of charge), the battery should be replaced.
  • 8) If test voltage is below the minimum and the stable battery open circuit voltage is below 12.4 volts, the battery should be charged and the load test repeated. If the battery fails again, it should be replaced.

Although the load test provides data that is useful for determining the condition of a battery that has been in service, it has certain drawbacks. First, the load test requires that the battery be sufficiently, and preferably fully, charged in order that it can supply the battery's maximum power to the load. Second, the battery becomes somewhat depleted as a result of the test discharge and therefore leaves it in a less than ideal condition. Third, the standard load test equipment is quite heavy and bulky to handle heavy current loads and as such is not very portable. Fourth, sparks may be produced during the load test. Fifth, the load test takes a finite time to discharge the battery and the equipment must often be cooled between tests to prevent overheating. Sixth, the battery is often at a temperature that departs from ambient testing conditions (70° F.) and as such operators are not always aware of the correct comparison voltage to determine if the battery should be replaced. Typically, operators remember the 70° F. value of 9.6 volts only. Therefore, it is desirable to obtain such load test voltage data by using a more amenable testing technique than the method described above.

More recently, techniques have been pioneered by Dr. Keith S. Champlin and Midtronics, Inc. for testing storage batteries by measuring the conductance and other properties of the batteries. Aspects of these techniques are described in a number of United States patents, for example, U.S. Pat. No. 3,873,911, issued Mar. 25, 1975, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat. No. 3,909,708, issued Sep. 30, 1975, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat. No. 4,816,768, issued Mar. 28, 1989, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat. No. 4,825,170, issued Apr. 25, 1989, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE WITH AUTOMATIC VOLTAGE SCALING; U.S. Pat. No. 4,881,038, issued Nov. 14, 1989, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE WITH AUTOMATIC VOLTAGE SCALING TO DETERMINE DYNAMIC CONDUCTANCE; U.S. Pat. No. 4,912,416, issued Mar. 27, 1990, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE WITH STATE-OF-CHARGE COMPENSATION; U.S. Pat. No. 5,140,269, issued Aug. 18, 1992, to Champlin, entitled ELECTRONIC TESTER FOR ASSESSING BATTERY/CELL CAPACITY; U.S. Pat. No. 5,343,380, issued Aug. 30, 1994, entitled METHOD AND APPARATUS FOR SUPPRESSING TIME VARYING SIGNALS IN BATTERIES UNDERGOING CHARGING OR DISCHARGING; U.S. Pat. No. 5,572,136, issued Nov. 5, 1996, entitled ELECTRONIC BATTERY TESTER WITH AUTOMATIC COMPENSATION FOR LOW STATE-OF-CHARGE; U.S. Pat. No. 5,574,355, issued Nov. 12, 1996, entitled METHOD AND APPARATUS FOR DETECTION AND CONTROL OF THERMAL RUNAWAY IN A BATTERY UNDER CHARGE; U.S. Pat. No. 5,585,416, issued Dec. 10, 1996, entitled APPARATUS AND METHOD FOR STEP-CHARGING BATTERIES TO OPTIMIZE CHARGE ACCEPTANCE; U.S. Pat. No. 5,585,728, issued Dec. 17, 1996, entitled ELECTRONIC BATTERY TESTER WITH AUTOMATIC COMPENSATION FOR LOW STATE-OF-CHARGE; U.S. Pat. No. 5,589,757, issued Dec. 31, 1996, entitled APPARATUS AND METHOD FOR STEP-CHARGING BATTERIES TO OPTIMIZE CHARGE ACCEPTANCE; U.S. Pat. No. 5,592,093, issued Jan. 7, 1997, entitled ELECTRONIC BATTERY TESTING DEVICE LOOSE TERMINAL CONNECTION DETECTION VIA A COMPARISON CIRCUIT; U.S. Pat. No. 5,598,098, issued Jan. 28, 1997, entitled ELECTRONIC BATTERY TESTER WITH VERY HIGH NOISE IMMUNITY; U.S. Pat. No. 5,656,920, issued Aug. 12, 1997, entitled METHOD FOR OPTIMIZING THE CHARGING LEAD-ACID BATTERIES AND AN INTERACTIVE CHARGER; U.S. Pat. No. 5,757,192, issued May 26, 1998, entitled METHOD AND APPARATUS FOR DETECTING A BAD CELL IN A STORAGE BATTERY; U.S. Pat. No. 5,821,756, issued Oct. 13, 1998, entitled ELECTRONIC BATTERY TESTER WITH TAILORED COMPENSATION FOR LOW STATE-OF-CHARGE; U.S. Pat. No. 5,831,435, issued Nov. 3, 1998, entitled BATTERY TESTER FOR JIS STANDARD; U.S. Pat. No. 5,914,605, issued Jun. 22, 1999, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 5,945,829, issued Aug. 31, 1999, entitled MIDPOINT BATTERY MONITORING; U.S. Pat. No. 6,002,238, issued Dec. 14, 1999, entitled METHOD AND APPARATUS FOR MEASURING COMPLEX IMPEDANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,037,751, issued Mar. 14, 2000, entitled APPARATUS FOR CHARGING BATTERIES; U.S. Pat. No. 6,037,777, issued Mar. 14, 2000, entitled METHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIES FROM COMPLEX IMPEDANCE/ADMITTANCE; U.S. Pat. No. 6,051,976, issued Apr. 18, 2000, entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Pat. No. 6,081,098, issued Jun. 27, 2000, entitled METHOD AND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,091,245, issued Jul. 18, 2000, entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Pat. No. 6,104,167, issued Aug. 15, 2000, entitled METHOD AND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,137,269, issued Oct. 24, 2000, entitled METHOD AND APPARATUS FOR ELECTRONICALLY EVALUATING THE INTERNAL TEMPERATURE OF AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Pat. No. 6,163,156, issued Dec. 19, 2000, entitled ELECTRICAL CONNECTION FOR ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,172,483, issued Jan. 9, 2001, entitled METHOD AND APPARATUS FOR MEASURING COMPLEX IMPEDANCE OF CELL AND BATTERIES; U.S. Pat. No. 6,172,505, issued Jan. 9, 2001, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,222,369, issued Apr. 24, 2001, entitled METHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIES FROM COMPLEX IMPEDANCE/ADMITTANCE; U.S. Pat. No. 6,225,808, issued May 1, 2001, entitled TEST COUNTER FOR ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,249,124, issued Jun. 19, 2001, entitled ELECTRONIC BATTERY TESTER WITH INTERNAL BATTERY; U.S. Pat. No. 6,259,254, issued Jul. 10, 2001, entitled APPARATUS AND METHOD FOR CARRYING OUT DIAGNOSTIC TESTS ON BATTERIES AND FOR RAPIDLY CHARGING BATTERIES; U.S. Pat. No. 6,262,563, issued Jul. 17, 2001, entitled METHOD AND APPARATUS FOR MEASURING COMPLEX ADMITTANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,294,896, issued Sep. 25, 2001; entitled METHOD AND APPARATUS FOR MEASURING COMPLEX SELF-IMMITANCE OF A GENERAL ELECTRICAL ELEMENT; U.S. Pat. No. 6,294,897, issued Sep. 25, 2001, entitled METHOD AND APPARATUS FOR ELECTRONICALLY EVALUATING THE INTERNAL TEMPERATURE OF AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Pat. No. 6,304,087, issued Oct. 16, 2001, entitled APPARATUS FOR CALIBRATING ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,310,481, issued Oct. 30, 2001, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,313,607, issued Nov. 6, 2001, entitled METHOD AND APPARATUS FOR EVALUATING STORED CHARGE IN AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Pat. No. 6,313,608, issued Nov. 6, 2001, entitled METHOD AND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,316,914, issued Nov. 13, 2001, entitled TESTING PARALLEL STRINGS OF STORAGE BATTERIES; U.S. Pat. No. 6,323,650, issued Nov. 27, 2001, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,329,793, issued Dec. 11, 2001, entitled METHOD AND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,331,762, issued Dec. 18, 2001, entitled ENERGY MANAGEMENT SYSTEM FOR AUTOMOTIVE VEHICLE; U.S. Pat. No. 6,332,113, issued Dec. 18, 2001, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,351,102, issued Feb. 26, 2002, entitled AUTOMOTIVE BATTERY CHARGING SYSTEM TESTER; U.S. Pat. No. 6,359,441, issued Mar. 19, 2002, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,363,303, issued Mar. 26, 2002, entitled ALTERNATOR DIAGNOSTIC SYSTEM, U.S. Pat. No. 6,392,414, issued May 21, 2002, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,417,669, issued Jul. 9, 2002, entitled SUPPRESSING INTERFERENCE IN AC MEASUREMENTS OF CELLS, BATTERIES AND OTHER ELECTRICAL ELEMENTS; U.S. Pat. No. 6,424,158, issued Jul. 23, 2002, entitled APPARATUS AND METHOD FOR CARRYING OUT DIAGNOSTIC TESTS ON BATTERIES AND FOR RAPIDLY CHARGING BATTERIES; U.S. Pat. No. 6,441,585, issued Aug. 17, 2002, entitled APPARATUS AND METHOD FOR TESTING RECHARGEABLE ENERGY STORAGE BATTERIES; U.S. Pat. No. 6,445,158, issued Sep. 3, 2002, entitled VEHICLE ELECTRICAL SYSTEM TESTER WITH ENCODED OUTPUT; U.S. Pat. No. 6,456,045, issued Sep. 24, 2002, entitled INTEGRATED CONDUCTANCE AND LOAD TEST BASED ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,466,025, issued Oct. 15, 2002, entitled ALTERNATOR TESTER; U.S. Pat. No. 6,466,026, issued Oct. 15, 2002, entitled PROGRAMMABLE CURRENT EXCITER FOR MEASURING AC IMMITTANCE OF CELLS AND BATTERIES; U.S. Ser. No. 09/703,270, filed Oct. 31, 2000, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 09/780,146, filed Feb. 9, 2001, entitled STORAGE BATTERY WITH INTEGRAL BATTERY TESTER; U.S. Ser. No. 09/816,768, filed Mar. 23, 2001, entitled MODULAR BATTERY TESTER; U.S. Ser. No. 09/756,638, filed Jan. 8, 2001, entitled METHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIES FROM COMPLEX IMPEDANCE/ADMITTANCE; U.S. Ser. No. 09/862,783, filed May 21, 2001, entitled METHOD AND APPARATUS FOR TESTING CELLS AND BATTERIES EMBEDDED IN SERIES/PARALLEL SYSTEMS; U.S. Ser. No. 09/960,117, filed Sep. 20, 2001, entitled IN-VEHICLE BATTERY MONITOR; U.S. Ser. No. 09/908,389, filed Jul. 18, 2001, entitled BATTERY CLAMP WITH INTEGRATED CIRCUIT SENSOR; U.S. Ser. No. 09/908,278, filed Jul. 18, 2001, entitled BATTERY CLAMP WITH EMBEDDED ENVIRONMENT SENSOR; U.S. Ser. No. 09/880,473, filed Jun. 13, 2001; entitled BATTERY TEST MODULE; U.S. Ser. No. 09/940,684, filed Aug. 27, 2001, entitled METHOD AND APPARATUS FOR EVALUATING STORED CHARGE IN AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Ser. No. 60/330,441, filed Oct. 17, 2001, entitled ELECTRONIC BATTERY TESTER WITH RELATIVE TEST OUTPUT; U.S. Ser. No. 60/348,479, filed Oct. 29, 2001, entitled CONCEPT FOR TESTING HIGH POWER VRLA BATTERIES; U.S. Ser. No. 10/046,659, filed Oct. 29, 2001, entitled ENERGY MANAGEMENT SYSTEM FOR AUTOMOTIVE VEHICLE; U.S. Ser. No. 09/993,468, filed Nov. 14, 2001, entitled KELVIN CONNECTOR FOR A BATTERY POST; U.S. Ser. No. 09/992,350, filed Nov. 26, 2001, entitled ELECTRONIC BATTERY TESTER, U.S. Ser. No. 60/341,902, filed Dec. 19, 2001, entitled BATTERY TESTER MODULE; U.S. Ser. No. 10/042,451, filed Jan. 8, 2002, entitled BATTERY CHARGE CONTROL DEVICE, U.S. Ser. No. 10/073,378, filed Feb. 8, 2002, entitled METHOD AND APPARATUS USING A CIRCUIT MODEL TO EVALUATE CELL/BATTERY PARAMETERS; U.S. Ser. No. 10/093,853, filed Mar. 7, 2002, entitled ELECTRONIC BATTERY TESTER WITH NETWORK COMMUNICATION; U.S. Ser. No. 60/364,656, filed Mar. 14, 2002, entitled ELECTRONIC BATTERY TESTER WITH LOW TEMPERATURE RATING DETERMINATION; U.S. Ser. No. 10/098,741, filed Mar. 14, 2002, entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Ser. No. 10/101,543, filed Mar. 19, 2002, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 10/112,114, filed Mar. 28, 2002; U.S. Ser. No. 10/109,734, filed Mar. 28, 2002; U.S. Ser. No. 10/112,105, filed Mar. 28, 2002, entitled CHARGE CONTROL SYSTEM FOR A VEHICLE BATTERY; U.S. Ser. No. 10/112,998, filed Mar. 29, 2002, entitled BATTERY TESTER WITH BATTERY REPLACEMENT OUTPUT; U.S. Ser. No. 10/119,297, filed Apr. 9, 2002, entitled METHOD AND APPARATUS FOR TESTING CELLS AND BATTERIES EMBEDDED IN SERIES/PARALLEL SYSTEMS; U.S. Ser. No. 10/128,790, filed Apr. 22, 2002, entitled METHOD OF DISTRIBUTING JUMP-START BOOSTER PACKS; U.S. Ser. No. 60/379,281, filed May 8, 2002, entitled METHOD FOR DETERMINING BATTERY STATE OF CHARGE; U.S. Ser. No. 10/143,307, filed May 10, 2002, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 60/387,046, filed Jun. 7, 2002, entitled METHOD AND APPARATUS FOR INCREASING THE LIFE OF A STORAGE BATTERY; U.S. Ser. No. 10/177,635, filed Jun. 21, 2002, entitled BATTERY CHARGER WITH BOOSTER PACK; U.S. Ser. No. 10/207,495, filed Jul. 29, 2002, entitled KELVIN CLAMP FOR ELECTRICALLY COUPLING TO A BATTERY CONTACT; U.S. Ser. No. 10/200,041, filed Jul. 19, 2002, entitled AUTOMOTIVE VEHICLE ELECTRICAL SYSTEM DIAGNOSTIC DEVICE; U.S. Ser. No. 10/217,913, filed Aug. 13, 2002, entitled, BATTERY TEST MODULE; U.S. Ser. No. 60/408,542, filed Sep. 5, 2002, entitled BATTERY TEST OUTPUTS ADJUSTED BASED UPON TEMPERATURE; U.S. Ser. No. 10/246,439, filed Sep. 18, 2002, entitled BATTERY TESTER UPGRADE USING SOFTWARE KEY; U.S. Ser. No. 60/415,399, filed Oct. 2, 2002, entitled QUERY BASED ELECTRONIC BATTERY TESTER; and U.S. Ser. No. 10/263,473, filed Oct. 2, 2002, entitled ELECTRONIC BATTERY TESTER WITH RELATIVE TEST OUTPUT; U.S. Ser. No. 60/415,796, filed Oct. 3, 2002, entitled QUERY BASED ELECTRONIC BATTERY TESTER; U.S. Ser. No. 10/271,342, filed Oct. 15, 2002, entitled IN VEHICLE BATTERY MONITOR; U.S. Ser. No. 10/270,777, filed Oct. 15, 2002, entitled PROGRAMMABLE CURRENT EXCITER FOR MEASURING AC IMMITTANCE OF CELLS AND BATTERIES; U.S. Ser. No. 10/310,515, filed Dec. 5, 2002, entitled BATTERY TEST MODULE; U.S. Ser. No. 10/310,490, filed Dec. 5, 2002, entitled BATTERY TEST MODULE; U.S. Ser. No. 10/310,385 entitled ELECTRONIC BATTERY TESTER, U.S. Ser. No. 60/437,255, filed Dec. 31, 2002, entitled REMAINING TIME PREDICTIONS, U.S. Ser. No. 60/437,224, filed Dec. 31, 2002, entitled DISCHARGE VOLTAGE PREDICTIONS, U.S. Ser. No. 60/437,611, entitled REMAINING TIME PREDICTIONS, which are incorporated herein in their entirety.

In general, battery testers, which determine the condition of the battery as a function of measured dynamic conductance of the battery, carry out the conductance measurement by injecting or drawing a small AC current (less than about 2 amperes) through the battery and measuring the resulting AC voltage. Since this technique only involves the use of a small AC current to determine conductance, it is easy to perform, does not discharge the battery, is relatively rapid and is free from sparking.

SUMMARY OF THE INVENTION

The present invention is directed to the use of a dynamic battery parameter, coupled with battery voltage, temperature and Cold Cranking Performance rating (CCA), to determine how a battery would perform under an actual load test. A method and apparatus for testing a storage battery is provided in which a battery is measured to obtain a battery dynamic parameter value such as conductance. The battery is measured to obtain a stable open circuit voltage and a battery temperature value. The load test voltage of the battery is estimated as a function of the battery dynamic parameter value, the open circuit voltage value, the battery temperature value and the battery CCA rating. This voltage value is compared to the minimum requirements for the battery listed above and an output indicative of a condition of the battery is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified schematic diagram showing battery test circuitry in accordance with the present invention.

FIG. 2 is a simplified block diagram showing the steps of a method of programming a battery tester in accordance with the invention.

FIG. 3 is a simplified block diagram showing the steps of a method of testing a battery in accordance with the present invention.

 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a method and apparatus for predicting how a battery would perform under a load test by employing a dynamic parameter testing technique. Although the example embodiments of the present invention described below relate to estimating load test values from battery conductance measurements, dynamic parameters other than battery conductance may be utilized without departing from the spirit and scope of the invention. Examples of other dynamic parameters include dynamic resistance, admittance, impedance, reactance, susceptance or their combinations.

FIG. 1 is a simplified block diagram of battery test circuitry 16 in accordance with an embodiment of the present invention. Apparatus 16 is shown coupled to battery 12, which includes a positive battery terminal 22 and a negative battery terminal 24. Battery 12 has a CCA rating and a load test voltage rating.

In preferred embodiments, circuitry 16 operates, with the exceptions and additions as discussed below, in accordance with battery testing methods described in one or more of the United States patents obtained by Dr. Champlin and Midtronics, Inc. and listed above. Circuitry 16 operates in accordance with one embodiment of the present invention and determines the conductance (G) of battery 12 and the open circuit voltage (OCV) between terminals 22 and 24 of battery 12. Circuitry 16 includes current source 50, differential amplifier 52, analog-to-digital converter 54 and microprocessor 56. Amplifier 52 is capacitively coupled to battery 12 through capacitors C1 and C2. Amplifier 52 has an output connected to an input of analog-to-digital converter 54. Microprocessor 56 is connected to system clock 58, memory 60, memory 62 and analog-to-digital converter 54. Microprocessor 56 is also capable of receiving an input from input devices 66 and 68. Microprocessor 56 also connects to output device 72.

In operation, current source 50 is controlled by microprocessor 56 and provides a current I in the direction shown by the arrow in FIG. 1. In one embodiment, this is a square wave or a pulse. Differential amplifier 52 is connected to terminals 22 and 24 of battery 12 through capacitors C1 and C2, respectively, and provides an output related to the voltage potential difference between terminals 22 and 24. In a preferred embodiment, amplifier 52 has a high input impedance. Circuitry 16 includes differential amplifier 70 having inverting and noninverting inputs connected to terminals 24 and 22, respectively. Amplifier 70 is connected to measure the OCV of battery 12 between terminals 22 and 24. The output of amplifier 70 is provided to analog-to-digital converter 54 such that the voltage across terminals 22 and 24 can be measured by microprocessor 56.

Circuitry 16 is connected to battery 12 through a four-point connection technique known as a Kelvin connection. This Kelvin connection allows current I to be injected into battery 12 through a first pair of terminals while the voltage V across the terminals 22 and 24 is measured by a second pair of connections. Because very little current flows through amplifier 52, the voltage drop across the inputs to amplifier 52 is substantially identical to the voltage drop across terminals 22 and 24 of battery 12. The output of differential amplifier 52 is converted to a digital format and is provided to microprocessor 56. Microprocessor 56 operates at a frequency determined by system clock 58 and in accordance with programming instructions stored in memory 60.

Microprocessor 56 determines the conductance of battery 12 by applying a current pulse I using current source 50. The microprocessor determines the change in battery voltage due to the current pulse I using amplifier 52 and analog-to-digital converter 54. The value of current I generated by current source 50 is known and is stored in memory 60. Microprocessor 56 calculates the conductance of battery 12 using the following equation:

Conductance = G = Δ ⁢ ⁢ I Δ ⁢ ⁢ V Equation ⁢ ⁢ 1
where ΔI is the change in current flowing through battery 12 due to current source 50 and ΔV is the change in battery voltage due to applied current ΔI. In some embodiments circuitry 16 also includes a temperature sensor 74, coupled to microprocessor 56, that can be thermally coupled to battery 12 to thereby measure a temperature of battery 12 and provide the measured battery temperature value(s) to microprocessor 56. In the preferred embodiment, the battery temperature would be measured using an infrared signal from the outside of the battery. In other embodiments, instead of being measured, the temperature of battery 12 may be estimated or input by a tester user through input 66, for example. Microprocessor 56 can also use other information input from input device 66 provided by, for example, an operator. This information may consist of the particular type of battery, location, time, the name of the operator, the CCA rating of the battery, the rated load test voltage of the battery, etc.

Under the control of microprocessor 56, battery tester 16 estimates a load test voltage of battery 12 as a function of the battery conductance G, the OCV, the battery temperature and the CCA rating of battery 12. Further, battery tester 16 compares the estimated load test voltage with the rated load test voltage of battery 12 and outputs the state of health of battery 12 based on this comparison. Details regarding the derivation of an algorithm utilized by battery tester 16 to estimate the load test voltage of battery 12 are provided below. The algorithm included below was derived by taking a representative sample of batteries of different sizes and ages and testing them for their conductance and reactions to various loads at various temperatures.

It was found that battery conductance varied with temperature in a substantially predictable curvilinear manner. At cold temperatures it would drop rapidly, while at high temperatures it was higher and more constant. This occurs primarily as a result of the variation of the resistance of the electrolyte with temperature. It was found that the specific conductance could be fitted to a third order polynomial equation with temperature. Using the given temperature of the battery, the conductance at any other temperature can then be predicted by multiplying and dividing by the appropriate temperature factors obtained from this temperature curve.

With fully charged batteries of a given conductance, it is found that the instantaneous loaded voltage is dependent on a voltage that is less than the OCV of the battery. This activation voltage is temperature dependent and can be linearly related:
V=Vact−I*R
or
V=Vact−I/G  (Equation 2)
where V is an instantaneous voltage, Vact is the temperature related fully charged activation voltage, I is the discharge current, R is the battery resistance and G is the battery conductance.

Because batteries are not always at full charge and at a standard temperature (temperature defined in a battery test standard), properties of the battery in a fully charged condition at a standard temperature need be estimated. It was found that using the initial voltage or OCV as a measure of the discharge of the battery and also using the temperature of the battery, the conductance could be compensated for by a mathematical relationship to predict that of a fully charged battery under standard conditions. For example, conductance can be expressed as:
Gcomp=G*f1(T,OCV)  Equation 3
G70=Gcomp*f2(70)/f2(T)  Equation 4
where Gcomp is conductance compensated to full charge at the OCV and temperature of the battery, G70 is conductance at full charge and 70° F., f1(T,OCV) is a function to compensate the conductance at a given temperature and voltage, and f2(T) is a function of the specific conductance at a given temperature.

Since the conductance can be corrected mathematically to full charge, the need to recharge moderately discharged batteries before testing or warming or cooling the battery to test conditions is eliminated.

Thus, knowing the temperature and the conductance (compensated mathematically to full charge) the initial voltage under load can be estimated. Vact is easily calculated for various temperatures by measuring the conductance or the resistance of the fully charged battery and then running the discharge for a short time (2 seconds, for example). Using Equation 2, Vact can be calculated by adding the I*R (or I/G) value to the initial voltage where I is half the CCA rating. By comparing many temperatures and battery types, it is found that Vact varies approximately linearly with temperature and therefore can be predicted using temperature alone.
Vact=k1*T+k2  Equation 5
where T is the battery temperature and k1 and k2 are constants.

Thus the instantaneous load test value at a standard test temperature (70° F.) can be predicted using the combined equations:
Vinit70=70*k1+k2−(CCA/2)/G(70)  Equation 6
Where Vinit70=the initial or instantaneous voltage predicted at full charge and 70° F. and G(70) is the projected conductance at full charge and 70° F.

As mentioned above, the load test must sustain its load for a period of time (15 seconds). For good batteries, the initial voltage (2-second voltage) and the 15-second voltage are not substantially different. However, as a battery approaches the end of life, its voltage can decay markedly during the discharge, thus causing a failure even though the initial voltage may be above the minimum specification level. This decay between the initial voltage and the 15-second voltage can be linearly related to the initial battery voltage at standard temperature for most batteries. Thus the decay voltage (DV) can be estimated by using the following relationship:
DV=k3*Vinit70−k4  Equation 7
where Vinit70 is the initial or instantaneous load test voltage at 70° F. and k3 and k4 are constants.

Combining the above Equations, the load test voltage (LTV) at a standard test temperature of 70° F. can be estimated as:
LTV70=Vinit70−DV
or
LTV70=k4+LTV70*(1−k3)  Equation 8
This value can then be compared to the rated load test voltage for the battery at the standard test temperature and a judgment on the state of health of the battery can be easily rendered. The rated load test voltage of 9.6 Volts at 70° F. for 12V batteries is used as a comparison. It can also be appreciated that the load test voltage at any other temperature of the battery can similarly be predicted.

FIG. 2 is a flowchart 100 showing steps of a method of programming battery tester 16 in accordance with an embodiment of the present invention. As shown in flow chart 100, at step 102, a characteristic curve for the variation of battery conductance with temperature is established. At step 104, the characteristic conductance-temperature curve is programmed into memory 60 of battery tester 16 via input 66. At step 106, mathematical relationships to estimate the load test voltage from the conductance, temperature, OCV and CCA rating of the battery are established (Equations 1-8 above). At step 108, the mathematical relationships are programmed into memory 60 of battery tester 16. At this point, battery tester 16 is ready to estimate battery load test voltages and provide load test results for batteries.

FIG. 3 is a flowchart 150 showing steps of a method of testing a battery in accordance with an embodiment of the present invention. At step 152, dynamic parameter of the battery is measured. At step 154, an open circuit voltage of the battery is obtained. At step 156, a temperature of the battery is measured. At step 158, a cranking size rating (such as the CCA rating) of the battery is obtained. At step 160, a load test voltage of the battery is estimated as a function of the measured battery dynamic parameter, the open circuit voltage of the battery, the measured battery temperature and the cranking size rating of the battery. Different techniques, some of which are set forth above, can be employed to carry out the steps shown in the flow chart of FIG. 3 while maintaining substantially the same functionality without departing from the scope and spirit of the present invention.

In embodiments of the present invention, battery tester 16 is configured to issue a warning that the battery should be recharged before a judgment on the state of health of the battery can be rendered, if it determines that the battery is in an over discharged condition. Also, battery faults such as shorts can be determined by suitably combining the voltage and conductance information using known techniques.

Thus, a rapid test can be performed using the parameters of conductance, OCV, temperature and the CCA rating of the battery to provide data that the industry has accepted for batteries in service.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. As mentioned above, although the example embodiments of the present invention described above relate to estimating load test values from battery conductance measurements, dynamic parameters other than battery conductance may be utilized without departing from the spirit and scope of the invention. Examples of other dynamic parameters include dynamic resistances, admittance, impedance, reactance, susceptance or their combinations. In general, a dynamic parameter of the battery can be obtained measuring a response of the battery to any suitable active or passive source.

Claims

1. A method of testing a storage battery, comprising:

(a) measuring a dynamic parameter of the battery using a low alternating current signal;
(b) obtaining an open circuit voltage of the battery;
(c) measuring a temperature of the battery;
(d) obtaining a cranking size rating of the battery; and
(e) estimating a load test voltage of the battery as a function of the measured battery dynamic parameter, the obtained open circuit voltage of the battery, the measured battery temperature, an activation voltage, which is calculated based on the measured temperature of the battery and the obtained open circuit voltage, and the cranking size rating of the battery, the estimated load test voltage indicative of power remaining in the battery.

2. The method of claim 1 wherein the estimating step (e) further comprises predicting a battery dynamic parameter at a standard battery temperature value as a function of the measured battery dynamic parameter and the measured battery temperature.

3. The method of claim 1 wherein the estimating step (e) further comprises predicting a battery dynamic parameter at a standard battery temperature value and at a full battery state of charge level as a function of the measured battery dynamic parameter, the measured battery temperature and a measured battery state of charge level.

4. The method of claim 3 wherein the measured battery state of charge level is determined from the open circuit voltage of the battery.

5. The method of claim 1 wherein the cranking size rating of the battery is a Cold Cranking Amp (CCA) rating of the battery.

6. The method of claim 1 further comprising providing an output indicative of a condition of the battery as a function of the estimated load test voltage of the battery.

7. The method of claim 6 wherein providing the output indicative of the condition of the battery further comprises receiving a rated load test voltage of the battery and comparing the estimated load test voltage with the rated load test voltage.

8. The method of claim 1 wherein the measured battery dynamic parameter value is battery conductance.

9. The method of claim 1 wherein the measured battery dynamic parameter value is battery resistance.

10. An electronic battery tester comprising:

a positive connector coupled to a positive terminal of the battery;
a negative connector coupled to a negative terminal of the battery;
a voltage sensor configured to measure an open circuit voltage of the battery;
a temperature sensor configured to measure a temperature of the battery;
an input configured to receive a cranking size rating of the battery; and
battery test circuitry configured to measure a dynamic parameter of the battery by applying a low alternating current signal to the battery using the first and second connectors, and to estimate a load test voltage of the battery as a function of the measured battery dynamic parameter, the measured open circuit voltage of the battery, the measured battery temperature, an activation voltage, which is calculated based on the measured temperature of the battery and the measured open circuit voltage, and the cranking size rating of the battery, the estimated load test voltage indicative of power remaining in the battery.

11. The apparatus of claim 10 wherein the battery test circuitry is further configured to provide an output indicative of a condition of the battery as a function of the estimated load test voltage of the battery.

12. The apparatus of claim 11 wherein the battery test circuitry is configured to provide the output indicative of the condition of the battery by receiving a rated load test voltage of the battery and comparing the estimated load test voltage with the rated load test voltage.

13. The apparatus of claim 10 wherein the battery test circuitry is further configured to estimate the load test voltage of the battery by predicting a battery dynamic parameter at a standard battery temperature value as a function of the measured battery dynamic parameter and the measured battery temperature.

14. The apparatus of claim 10 wherein the battery test circuitry is further configured to estimate the load test voltage of the battery by predicting a battery dynamic parameter at a standard battery temperature value and at a full battery state of charge level as a function of the measured battery dynamic parameter, the measured battery temperature and a measured battery state of charge level.

15. The apparatus of claim 14 wherein the battery test circuitry is further configured to obtain the measured battery state of charge level from the open circuit voltage of the battery.

16. The apparatus of claim 10 wherein the cranking size rating of the battery is a Cold Cranking Amp (CCA) rating of the battery.

17. The apparatus of claim 10 wherein the measured battery dynamic parameter value is battery conductance.

18. The apparatus of claim 10 wherein the measured battery dynamic parameter value is battery resistance.

19. The apparatus of claim 10 wherein the positive connector is a first Kelvin connector and the negative connector is a second Kelvin connector.

Referenced Cited
U.S. Patent Documents
2514745 July 1950 Dalzell
3356936 December 1967 Smith
3562634 February 1971 Latner
3593099 July 1971 Scholl
3607673 September 1971 Seyl
3676770 July 1972 Sharaf et al.
3729989 May 1973 Little
3753094 August 1973 Furuishi et al.
3808522 April 1974 Sharaf
3811089 May 1974 Strezelewicz
3873911 March 1975 Champlin
3876931 April 1975 Godshalk
3886443 May 1975 Miyakawa et al.
3889248 June 1975 Ritter
3906329 September 1975 Bader
3909708 September 1975 Champlin
3936744 February 3, 1976 Perlmutter
3946299 March 23, 1976 Christianson et al.
3947757 March 30, 1976 Grube et al.
3969667 July 13, 1976 McWilliams
3979664 September 7, 1976 Harris
3984762 October 5, 1976 Dowgiallo, Jr.
3984768 October 5, 1976 Staples
3989544 November 2, 1976 Santo
4008619 February 22, 1977 Alcaide et al.
4024953 May 24, 1977 Nailor, III
4047091 September 6, 1977 Hutchines et al.
4053824 October 11, 1977 Dupuis et al.
4070624 January 24, 1978 Taylor
4086531 April 25, 1978 Bernier
4112351 September 5, 1978 Back et al.
4114083 September 12, 1978 Benham et al.
4126874 November 21, 1978 Suzuki et al.
4178546 December 11, 1979 Hulls et al.
4193025 March 11, 1980 Frailing et al.
4207611 June 10, 1980 Gordon
4217645 August 12, 1980 Barry et al.
4297639 October 27, 1981 Branham
4315204 February 9, 1982 Sievers et al.
4316185 February 16, 1982 Watrous et al.
4322685 March 30, 1982 Frailing et al.
4351405 September 28, 1982 Fields et al.
4361809 November 30, 1982 Bil et al.
4363407 December 14, 1982 Barkler et al.
4369407 January 18, 1983 Korbell
4379989 April 12, 1983 Kurz et al.
4379990 April 12, 1983 Sievers et al.
4385269 May 24, 1983 Aspinwall et al.
4390828 June 28, 1983 Converse et al.
4392101 July 5, 1983 Saar et al.
4396880 August 2, 1983 Windebank
4408157 October 4, 1983 Beaubien
4412169 October 25, 1983 Dell'Orto
4423378 December 27, 1983 Marino et al.
4423379 December 27, 1983 Jacobs et al.
4424491 January 3, 1984 Bobbett et al.
4459548 July 10, 1984 Lentz et al.
4514694 April 30, 1985 Finger
4520353 May 28, 1985 McAuliffe
4564798 January 14, 1986 Young
4633418 December 30, 1986 Bishop
4659977 April 21, 1987 Kissel et al.
4663580 May 5, 1987 Wortman
4665370 May 12, 1987 Holland
4667143 May 19, 1987 Cooper et al.
4667279 May 19, 1987 Maier
4678998 July 7, 1987 Muramatsu
4679000 July 7, 1987 Clark
4680528 July 14, 1987 Mikami et al.
4686442 August 11, 1987 Radomski
4697134 September 29, 1987 Burkum et al.
4707795 November 17, 1987 Alber et al.
4709202 November 24, 1987 Koenck et al.
4710861 December 1, 1987 Kanner
4719428 January 12, 1988 Liebermann
4743855 May 10, 1988 Randin et al.
4745349 May 17, 1988 Palanisamy et al.
4816768 March 28, 1989 Champlin
4820966 April 11, 1989 Fridman
4825170 April 25, 1989 Champlin
4847547 July 11, 1989 Eng, Jr. et al.
4849700 July 18, 1989 Morioka et al.
4876495 October 24, 1989 Palanisamy et al.
4881038 November 14, 1989 Champlin
4888716 December 19, 1989 Ueno
4912416 March 27, 1990 Champlin
4913116 April 3, 1990 Katogi et al.
4929931 May 29, 1990 McCuen
4931738 June 5, 1990 MacIntyre et al.
4937528 June 26, 1990 Palanisamy
4947124 August 7, 1990 Hauser
4956597 September 11, 1990 Heavey et al.
4968941 November 6, 1990 Rogers
4968942 November 6, 1990 Palanisamy
5004979 April 2, 1991 Marino et al.
5032825 July 16, 1991 Xuznicki
5037778 August 6, 1991 Stark et al.
5047722 September 10, 1991 Wurst et al.
5087881 February 11, 1992 Peacock
5095223 March 10, 1992 Thomas
5126675 June 30, 1992 Yang
5140269 August 18, 1992 Champlin
5144218 September 1, 1992 Bosscha
5144248 September 1, 1992 Alexandres et al.
5160881 November 3, 1992 Schramm et al.
5170124 December 8, 1992 Blair et al.
5179335 January 12, 1993 Nor
5194799 March 16, 1993 Tomantschger
5204611 April 20, 1993 Nor et al.
5214370 May 25, 1993 Harm et al.
5214385 May 25, 1993 Gabriel et al.
5241275 August 31, 1993 Fang
5254952 October 19, 1993 Salley et al.
5266880 November 30, 1993 Newland
5281919 January 25, 1994 Palanisamy
5281920 January 25, 1994 Wurst
5295078 March 15, 1994 Stich et al.
5298797 March 29, 1994 Redl
5300874 April 5, 1994 Shimamoto et al.
5302902 April 12, 1994 Groehl
5315287 May 24, 1994 Sol
5321626 June 14, 1994 Palladino
5331268 July 19, 1994 Patino et al.
5336993 August 9, 1994 Thomas et al.
5338515 August 16, 1994 Dalla Betta et al.
5339018 August 16, 1994 Brokaw
5343380 August 30, 1994 Champlin
5347163 September 13, 1994 Yoshimura
5352968 October 4, 1994 Reni et al.
5365160 November 15, 1994 Leppo et al.
5365453 November 15, 1994 Startup et al.
5381096 January 10, 1995 Hirzel
5412323 May 2, 1995 Kato et al.
5426371 June 20, 1995 Salley et al.
5426416 June 20, 1995 Jefferies et al.
5432426 July 11, 1995 Yoshida
5434495 July 18, 1995 Toko
5435185 July 25, 1995 Eagan
5442274 August 15, 1995 Tamai
5445026 August 29, 1995 Eagan
5449996 September 12, 1995 Matsumoto et al.
5449997 September 12, 1995 Gilmore et al.
5451881 September 19, 1995 Finger
5457377 October 10, 1995 Jonsson
5469043 November 21, 1995 Cherng et al.
5485090 January 16, 1996 Stephens
5488300 January 30, 1996 Jamieson
5519383 May 21, 1996 De La Rosa
5528148 June 18, 1996 Rogers
5537967 July 23, 1996 Tashiro et al.
5541489 July 30, 1996 Dunstan
5546317 August 13, 1996 Andrieu
5548273 August 20, 1996 Nicol et al.
5550485 August 27, 1996 Falk
5561380 October 1, 1996 Sway-Tin et al.
5562501 October 8, 1996 Kinoshita et al.
5563496 October 8, 1996 McClure
5572136 November 5, 1996 Champlin
5574355 November 12, 1996 McShane et al.
5583416 December 10, 1996 Klang
5585728 December 17, 1996 Champlin
5589757 December 31, 1996 Klang
5592093 January 7, 1997 Klingbiel
5596260 January 21, 1997 Moravec et al.
5598098 January 28, 1997 Champlin
5602462 February 11, 1997 Stich et al.
5606242 February 25, 1997 Hull et al.
5621298 April 15, 1997 Harvey
5633985 May 27, 1997 Severson et al.
5637978 June 10, 1997 Kellett et al.
5642031 June 24, 1997 Brotto
5650937 July 22, 1997 Bounaga
5652501 July 29, 1997 McClure et al.
5653659 August 5, 1997 Kunibe et al.
5656920 August 12, 1997 Cherng et al.
5675234 October 7, 1997 Greene
5677077 October 14, 1997 Faulk
5699050 December 16, 1997 Kanazawa
5701089 December 23, 1997 Perkins
5705929 January 6, 1998 Caravello et al.
5710503 January 20, 1998 Sideris et al.
5711648 January 27, 1998 Hammerslag
5717336 February 10, 1998 Basell et al.
5717937 February 10, 1998 Fritz
5739667 April 14, 1998 Matsuda et al.
5747909 May 5, 1998 Syverson et al.
5754417 May 19, 1998 Nicollini
5757192 May 26, 1998 McShane et al.
5760587 June 2, 1998 Harvey
5773978 June 30, 1998 Becker
5789899 August 4, 1998 van Phuoc et al.
5793359 August 11, 1998 Ushikubo
5796239 August 18, 1998 van Phuoc et al.
5808469 September 15, 1998 Kopera
5818234 October 6, 1998 McKinnon
5821756 October 13, 1998 McShane et al.
5821757 October 13, 1998 Alvarez et al.
5825174 October 20, 1998 Parker
5831435 November 3, 1998 Troy
5862515 January 19, 1999 Kobayashi et al.
5872443 February 16, 1999 Williamson
5895440 April 20, 1999 Proctor et al.
5914605 June 22, 1999 Bertness
5927938 July 27, 1999 Hammerslag
5929609 July 27, 1999 Joy et al.
5939855 August 17, 1999 Proctor et al.
5939861 August 17, 1999 Joko et al.
5945829 August 31, 1999 Bertness
5951229 September 14, 1999 Hammerslag
5961561 October 5, 1999 Wakefield, II
5961604 October 5, 1999 Anderson et al.
5969625 October 19, 1999 Russo
6002238 December 14, 1999 Champlin
6008652 December 28, 1999 Theofanopoulos et al.
6009369 December 28, 1999 Boisvert et al.
6031354 February 29, 2000 Wiley et al.
6037751 March 14, 2000 Klang
6037777 March 14, 2000 Champlin
6051976 April 18, 2000 Bertness
6061638 May 9, 2000 Joyce
6072299 June 6, 2000 Kurie et al.
6072300 June 6, 2000 Tsuji
6081098 June 27, 2000 Bertness et al.
6091245 July 18, 2000 Bertness
6094033 July 25, 2000 Ding et al.
6104167 August 15, 2000 Bertness et al.
6114834 September 5, 2000 Parise
6137269 October 24, 2000 Champlin
6140797 October 31, 2000 Dunn
6144185 November 7, 2000 Dougherty et al.
6150793 November 21, 2000 Lesesky et al.
6161640 December 19, 2000 Yamaguchi
6163156 December 19, 2000 Bertness
6167349 December 26, 2000 Alvarez
6172483 January 9, 2001 Champlin
6172505 January 9, 2001 Bertness
6181545 January 30, 2001 Amatucci et al.
6222369 April 24, 2001 Champlin
6225808 May 1, 2001 Varghese et al.
6236332 May 22, 2001 Conkright et al.
6249124 June 19, 2001 Bertness
6250973 June 26, 2001 Lowery et al.
6254438 July 3, 2001 Gaunt
6259254 July 10, 2001 Klang
6262563 July 17, 2001 Champlin
6263268 July 17, 2001 Nathanson
6294896 September 25, 2001 Champlin
6294897 September 25, 2001 Champlin
6304087 October 16, 2001 Bertness
6307349 October 23, 2001 Koenck et al.
6310481 October 30, 2001 Bertness
6313607 November 6, 2001 Champlin
6313608 November 6, 2001 Varghese et al.
6316914 November 13, 2001 Bertness
6323650 November 27, 2001 Bertness et al.
6329793 December 11, 2001 Bertness et al.
6331762 December 18, 2001 Bertness
6332113 December 18, 2001 Bertness
6346795 February 12, 2002 Haraguchi et al.
6347958 February 19, 2002 Tsai
6351102 February 26, 2002 Troy
6359441 March 19, 2002 Bertness
6359442 March 19, 2002 Henningson et al.
6363303 March 26, 2002 Bertness
6384608 May 7, 2002 Namaky
6388448 May 14, 2002 Cervas
6392414 May 21, 2002 Bertness
6411098 June 25, 2002 Laletin
6417669 July 9, 2002 Champlin
6424157 July 23, 2002 Gollomp et al.
6424158 July 23, 2002 Klang
6441585 August 27, 2002 Bertness
6445158 September 3, 2002 Bertness et al.
6456045 September 24, 2002 Troy et al.
6466025 October 15, 2002 Klang
6466026 October 15, 2002 Champlin
6495990 December 17, 2002 Champlin
6534992 March 18, 2003 Meissner et al.
6534993 March 18, 2003 Bertness
6544078 April 8, 2003 Palmisano et al.
6556019 April 29, 2003 Bertness
6566883 May 20, 2003 Vonderhaar et al.
6586941 July 1, 2003 Bertness et al.
6597150 July 22, 2003 Bertness et al.
20020171428 November 21, 2002 Bertness
Foreign Patent Documents
29 26 716 January 1981 DE
0 022 450 January 1981 EP
0 637 754 February 1995 EP
0 772 056 May 1997 EP
2 749 397 December 1997 FR
2 088 159 June 1982 GB
59-17892 January 1984 JP
59-17893 January 1984 JP
59-17894 January 1984 JP
59017894 January 1984 JP
59215674 December 1984 JP
60225078 November 1985 JP
62-180284 August 1987 JP
63027776 February 1988 JP
03274479 December 1991 JP
03282276 December 1991 JP
4-8636 January 1992 JP
04131779 May 1992 JP
04372536 December 1992 JP
5216550 August 1993 JP
7-128414 May 1995 JP
09061505 March 1997 JP
10056744 February 1998 JP
2089015 August 1997 RU
WO 93/22666 November 1993 WO
WO 94/05069 March 1994 WO
WO 98/04910 February 1998 WO
WO 98/58270 December 1998 WO
WO 99/23738 May 1999 WO
WO 00/62049 October 2000 WO
WO 00/67359 November 2000 WO
WO 01/51947 July 2001 WO
Other references
  • “Electrochemical Impedance Spectroscopy in Battery Development and Testing”, Batteries International, Apr. 1997, pp. 59 and 62-63.
  • “Battery Impedance”, by E. Willihnganz et al., Electrical Engineering, Sep. 1959, pp. 922-925.
  • “Determining The End of Battery Life”, by S. DeBardelaben, IEEE, 1986, pp. 365-368.
  • “A Look at the Impedance of a Cell”, by S. Debardelaben, IEEE, 1988, pp. 394-397.
  • “The Impedance of Electrical Storage Cells”, by N.A. Hampson et al., Journal of Applied Electrochemistry, 1980, pp. 3-11.
  • “A Package for Impedance/Admittance Data Analysis”, by B. Boukamp, Solid State Ionics, 1986, pp. 136-140.
  • “Precision of Impedance Spectroscopy Estimates of Bulk, Reaction Rate, and Diffusion Parameters”, by J. Macdonald et al., J. Electroanal, Chem., 1991, pp. 1-11.
  • Internal Resistance: Harbinger of Capacity Loss in Starved Electrolyte Sealed Lead Acid Batteries, by Vaccaro, F.J. et al., AT & T Bell Laboratories, 1987 IEEE, Ch. 2477, pp. 128, 131.
  • IEEE Recommended Practice For Maintenance, Testings, and Replacement of Large Lead Storage Batteries for Generating Stations and Substations, The Institute of Electrical and Electronics Engineers, Inc., ANSI/IEEE Std. 450-1987, Mar. 9, 1987.
  • “Field and Laboratory Studies to Assess the State of Health of Valve-Regulated Lead Acid Batteries: Part I Conductance/Capacity Correlation Studies”, by D. Feder et al., IEEE, Aug. 1992, pp. 218-233.
  • “JIS Japanese Industrial Standard-Lead Acid Batteries for Automobiles”, Japanese Standards Association UDC, 621.355.2:629.113.006, Nov. 1995.
  • “Performance of Dry Cells”; by C. Hambuechen, Preprint of Am. Electrochem. Soc., Apr. 18-20, 1912, paper No. 19, pp. 1-5.
  • “A Bridge for Measuring Storage Battery Resistance”, by E. Willihncanz, The Electrochemical Society, preprint 79-20, Apr. 1941, pp. 253-258.
  • National Semiconductor Corporation, “High Q Notch Filter”, Mar. 1969, Linear Brief 5, Mar. 1969.
  • Burr-Brown Corporation, “Design a 60 Hz Notch Filter with the UAF42”, Jan. 1994, AB-071, 1994.
  • National Semiconductor Corporation, “LMF90-4th-Order Elliptic Notch Filter”, Dec. 1994, RRD-B30M115, Dec. 1994.
  • “Alligator Clips with Wire Penetrators” J.S. Popper, Inc. product information, downloaded from http://www.jspopper.com/, undated.
  • “#12: LM78S40 Simple Switcher DC to DC Converter”, ITM e-Catalog, downloaded from http://www.pcbcafe.com, undated.
  • “Simple DC-DC Converts Allows Use of Single Battery”, Electronix Express, downloaded from http://www.elexp.com/t—dc-dc.htm, undated.
  • “DC-DC Converter Basics”, Power Designers, downloaded from http://www.powederdesigners.com/InforWeb.design—center/articles/DC-DC/converter.shtm, undated.
  • “Notification of Transmittal of the International Search Report or the Declaration”, PCT/US02/29461.
  • “Notification of Transmittal of the International Search Report or the Declaration”, PCT/US03/07546.
  • “Notification of Transmittal of the International Search Report or the Declaration”, PCT/US03/06577.
Patent History
Patent number: 7723993
Type: Grant
Filed: Sep 2, 2003
Date of Patent: May 25, 2010
Patent Publication Number: 20040046566
Assignee: Midtronics, Inc. (Willowbrook, IL)
Inventor: James K. Klang (Downers Grove, IL)
Primary Examiner: Patrick J Assouad
Assistant Examiner: Aaron Piggush
Attorney: Westman, Champlin & Kelly P.A.
Application Number: 10/653,342